Long-term wavelength stabilization of a commercial pulsed dye laser

An inexpensive device is described that stabilizes the wavelength of a commercial nanosecond-pulsed dye laser. The instrument monitors the frequency-dependent interference pattern that is generated when a portion of the dye laser output passes through an external Fabry-Perot étalon. In order to maintain a fixed wavelength, a personal computer adjusts the dye laser's grating position when the interference pattern indicates that a shift in laser wavelength has occurred. Tests indicate that this device reduces the drift of the laser's mean wavelength to < 0.0001-nm/ degrees C ambient temperature change. The feedback mechanism incorporated in this design can sustain stationary frequency stabilization for indefinite periods of time.